<!DOCTYPE html>
<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg">
    <rect x="0" y="0" width="100" height="100" fill="blue" />
    <circle cx="50" cy="50" r="30" fill="rgba(255,0,0,0.5)" />
    <circle cx="70" cy="60" r="30" fill="rgba(255,0,0,0.5)" />
</svg>